API/ABI changes review for ORC

[Andrey Ponomarenko]

The review of API/ABI changes for ORC library since 0.4.0 version: https://abi-laboratory.pro/tracker/timeline/orc/

Created with the help of open-source abi-tracker tool: https://github.com/lvc/abi-tracker. Hope it will be helpful for users and maintainers of the library.

## Environment
* Linux x86_64
* GCC 4.9
* ORC 0.4.0 and higher